Had a Proton and sold it to get the Groove Regulator. Both are great. Don't see how you could go wrong with either one. It was quicker for me to dial in the Proton but the GR has much more flexibility. I also have a DiscomBOBulator that I use for guitar. Never tried it on the bass. I like it as we'll and don't see why it wouldn't work well on the bass. Easy to dial in as well. Good luck with your search.